Theory Antiquote

theory Antiquote
imports Main
(*  Title:      HOL/ex/Antiquote.thy
Author: Markus Wenzel, TU Muenchen
*)


header {* Antiquotations *}

theory Antiquote
imports Main
begin

text {*
A simple example on quote / antiquote in higher-order abstract
syntax.
*}


definition var :: "'a => ('a => nat) => nat" ("VAR _" [1000] 999)
where "var x env = env x"

definition Expr :: "(('a => nat) => nat) => ('a => nat) => nat"
where "Expr exp env = exp env"

syntax
"_Expr" :: "'a => 'a" ("EXPR _" [1000] 999)

parse_translation {*
[Syntax_Trans.quote_antiquote_tr
@{syntax_const "_Expr"} @{const_syntax var} @{const_syntax Expr}]
*}


print_translation {*
[Syntax_Trans.quote_antiquote_tr'
@{syntax_const "_Expr"} @{const_syntax var} @{const_syntax Expr}]
*}


term "EXPR (a + b + c)"
term "EXPR (a + b + c + VAR x + VAR y + 1)"
term "EXPR (VAR (f w) + VAR x)"

term "Expr (λenv. env x)" -- {* improper *}
term "Expr (λenv. f env)"
term "Expr (λenv. f env + env x)" -- {* improper *}
term "Expr (λenv. f env y z)"
term "Expr (λenv. f env + g y env)"
term "Expr (λenv. f env + g env y + h a env z)"

end